Physical characteristics

Adult bedbugs are reddish brown, flattened, oval, and wingless, with microscopic hairs that give them a banded appearance. A common misconception is that they are not visible to the naked eye, but adults grow to 4 to 5 mm (one-eighth to three-sixteenths of an inch) in length and do not move quickly enough to escape the notice of an attentive observer. Newly hatched nymphs are translucent and lighter in color and continue to become browner and molt as they reach maturity. When it comes to size, they are often compared to lentils or appleseeds.

Feeding habits

Bedbugs are generally active only at night, with a peak attack period about an hour before dawn, though given the opportunity, they may attempt to feed at other times of day. Attracted by warmth and the presence of carbon dioxide, the bug pierces the skin of its host with two hollow tubes. With one tube it injects its saliva, which contains anticoagulants and anesthetics, while with the other it withdraws the blood of its host. After feeding for about five minutes, the bug returns to its hiding place. The bites cannot usually be felt until some minutes or hours later, as a dermatological reaction to the injected agents. Although bedbugs can live for up to 18 months without feeding, they typically seek blood every five to ten days.

Bedbugs are often erroneously associated with filth. They are attracted by exhaled carbon dioxide, not by dirt, and they feed on blood, not waste. In short, the cleanliness of their environments has no effect on bedbugs. Their numbers may be reduced temporarily by vacuuming, but will recover and require vacuuming again.

Health effects on humans

While bedbugs have been known to harbor pathogens in their bodies, including plague and hepatitis B, they have not been linked to the transmission of any disease and are not regarded as a medical threat. Some individuals, however, can get skin infections and scars from scratching bites. While bedbugs are not regarded as a vector of transmissible diseases, they may be a significant source of stress, alarm and/or distress. With some individuals, it may precipitate mild to moderate cases of delusional parasitosis.

Reproductive habits

Female bedbugs can lay up to five eggs in a day and 500 during a lifetime. The eggs are visible to the naked eye measuring 1 mm in length (approx. 2 grains of salt) and are a milky-white tone in color.

Size of Infestations

The numerical size of a bedbug infestation is to some degree variable, as it is a function of the elapsed time from the initial infestation. With regards to the elapsed time from the initial infestation, even a single female bedbug brought into a home has a potential for reproduction, with its resulting offspring then breeding, resulting in a geometric progression of population expansion if control is not undertaken. Sometimes people are not aware of the insects, but do notice the bites. The visible bedbug infestation does not represent the infestation as a whole, as there may be infestations elsewhere in a home, however, the insects do have a tendency to stay close to their hosts (hence the name "bed" bugs)

Living with infestation

If it is necessary to live with bedbugs in the short term, it is possible to create makeshift temporary barriers around a bed. Because bedbugs cannot fly or jump, an elevated bed can be protected by applying double-sided sticky tape (carpet tape) around each leg, or by keeping each leg on a plastic furniture block in a tray of water. Bed frame can be effectively ridded of adult bedbugs and eggs by use of steam. Small steam cleaners are available and are very effective for this local treatment. A suspect mattress can be protected by wrapping it in a painter's disposable plastic dropcloth, neatly sealing shut all the seams with packing tape, and putting it on a protected bed after a final visual inspection. Bedding can be sanitized by a 120 °F (49 °C) laundry dryer. Once sanitized, bedding should not be allowed to drape to the floor. An effective way to quarantine a protected bed is to store sanitized sleeping clothes in the bed during the day, and bathing before entering the bed.

Vermin and pets may complicate a barrier strategy. Bedbugs prefer human hosts, but will resort to other warm-blooded hosts if humans are not available, and some species can live up to eighteen months without feeding at all. A co-infestation of mice can provide an auxiliary food source to keep bedbugs established for longer. Likewise, a house cat or human guest might easily defeat a barrier by sitting on a protected bed. Such considerations should be part of any barrier strategy.